Strange Posted June 29, 2017 Share Posted June 29, 2017 If a graviton does not have to exist out side a black hole, why does it need to exist at all?. It doesn't need to exist. As far as we know, they don't exist. But IF space-time can be described by quantum field theory then the quanta would be what we call gravitons. (I don't know where "not existing outside a black hole" came from. Or even what it means.) A virtual particle or disturbance in a field could easily be caused by fermions whizzing past each other inside a nucleus, with no need for actual gravitons. A virtual graviton is just a wave or fluctuation in a field caused by the movement of particles. Waves expand outwards from the source of a disturbance, and there energy level reduces the further the wave travels and expands. That seems pretty comprehensively meaningless. Maybe you should try and learn what some of those words mean so you can put them together in a sentence that makes sense. Link to comment Share on other sites More sharing options...
imatfaal Posted June 30, 2017 Share Posted June 30, 2017 It doesn't need to exist. As far as we know, they don't exist. But IF space-time can be described by quantum field theory then the quanta would be what we call gravitons.... That is my understanding too. I would add that quantum field theory for the other 3 fundamental forces has turned out to be one of the most accurate and explanatory models in human history - so the search for a theory of quantum gravity (and thenceforward unification) is a path worth following. Maybe one of the experts can weigh in on this further question - with the data from experiments such as LIGO, BICEP2, Gravity Probe B etc. has anything cropped up that was a prediction based on solely the existence and current understanding of the graviton from qft rather than based on the understanding of GR (or on both classical and quantum theory). I know the sort of gravitational radiation fits with spin2 massless particle - but that was predicted by GR and graviton made to fit rather than other way around. Is there anything upon which GR is silent but qft might have got right? Link to comment Share on other sites More sharing options...
Handy andy Posted June 30, 2017 Author Share Posted June 30, 2017 (edited) Gravity is interesting because it is not properly understood by science, there are many theories around, so for anyone to claim they personally understand gravity demonstrates a lack of understanding of gravity or arrogance. I started the discussion but will step out, good luck with understanding gravity. I would suggest getting a consistent understanding of the graviton might be your starting point for discussion. I did post a link from Wikipedia which was reasonably concise ref the graviton but seems to have been not suitable for your level of understanding. Various differing ideas ref the graviton have been posted, the link would have answered your questions. https://phys.org/news/2017-03-team-dark.html#nRlv https://phys.org/news/2017-06-ditch-dark-energy-relativity.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter TTFU is a joke, that normal folk find amusing ROFL. Edited June 30, 2017 by Handy andy -1 Link to comment Share on other sites More sharing options...
imatfaal Posted June 30, 2017 Share Posted June 30, 2017 Gravity is interesting because it is not properly understood by science, there are many theories around, so for anyone to claim they personally understand gravity demonstrates a lack of understanding of gravity or arrogance. I started the discussion but will step out, good luck with understanding gravity. I would suggest getting a consistent understanding of the graviton might be your starting point for discussion. I did post a link from Wikipedia which was reasonably concise ref the graviton but seems to have been not suitable for your level of understanding. Various differing ideas ref the graviton have been posted, the link would have answered your questions. https://phys.org/news/2017-03-team-dark.html#nRlv https://phys.org/news/2017-06-ditch-dark-energy-relativity.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter TTFU is a joke, that normal folk find amusing ROFL. Link to comment Share on other sites More sharing options...
Strange Posted June 30, 2017 Share Posted June 30, 2017 Maybe one of the experts can weigh in on this further question - with the data from experiments such as LIGO, BICEP2, Gravity Probe B etc. has anything cropped up that was a prediction based on solely the existence and current understanding of the graviton from qft rather than based on the understanding of GR (or on both classical and quantum theory). I know the sort of gravitational radiation fits with spin2 massless particle - but that was predicted by GR and graviton made to fit rather than other way around. Is there anything upon which GR is silent but qft might have got right? Interesting question. I am guessing the answer is no, otherwise we would have seen headlines. But there might be some cautious ideas out there that haven't been exaggerated by the press. Gravity is interesting because it is not properly understood by science, there are many theories around, so for anyone to claim they personally understand gravity demonstrates a lack of understanding of gravity or arrogance. I started the discussion but will step out, good luck with understanding gravity. I would suggest getting a consistent understanding of the graviton might be your starting point for discussion. I did post a link from Wikipedia which was reasonably concise ref the graviton but seems to have been not suitable for your level of understanding. Various differing ideas ref the graviton have been posted, the link would have answered your questions. An impressive combination of being arrogant, offensive and wrong. https://phys.org/news/2017-03-team-dark.html#nRlv https://phys.org/news/2017-06-ditch-dark-energy-relativity.html?utm_source=nwletter&utm_medium=email&utm_campaign=daily-nwletter While both very interesting, that has nothing to do with the topic of this thread. TTFU is a joke, that normal folk find amusing ROFL. TBH I would find it pretty offensive in any context. Maybe that makes me abnormal. Or maybe it means I care about people's feelings. You decide. Link to comment Share on other sites More sharing options...
beecee Posted June 30, 2017 Share Posted June 30, 2017 Open Forum any one can respond. If it cant get out of a black hole how does gravity in a black hole work? etc Gravity does not have to get out of a BH...the gravity of a BH is a fossil field from the star/s that originally collapsed to form the BH. Plus of course all gravity is, is spacetime itself...It in itself is the BH. Gravity/spacetime is also nonlinear. And of course the quantized state of gravity/spacetime is still only a hypothetical concept. Link to comment Share on other sites More sharing options...
Handy andy Posted July 2, 2017 Author Share Posted July 2, 2017 Interesting question. I am guessing the answer is no, otherwise we would have seen headlines. But there might be some cautious ideas out there that haven't been exaggerated by the press. An impressive combination of being arrogant, offensive and wrong. While both very interesting, that has nothing to do with the topic of this thread. TBH I would find it pretty offensive in any context. Maybe that makes me abnormal. Or maybe it means I care about people's feelings. You decide. I obviously have the advantage here then, since clearly I find the insults directed at me amusing hilariously so. I was not however taking the micky out of you. The thread has been hijacked and completely off track. Best Wishes Link to comment Share on other sites More sharing options...
Strange Posted July 2, 2017 Share Posted July 2, 2017 I obviously have the advantage here then, since clearly I find the insults directed at me amusing hilariously so. I didn't think it was as an insult, nor directed at me. I just think it is a ridiculous thing to say to anyone, especially kids. The thread has been hijacked and completely off track. You manage to do that to all your threads. You should learn to focus a bit. 1 Link to comment Share on other sites More sharing options...
Phi for All Posted July 3, 2017 Share Posted July 3, 2017 ! Moderator Note There is a willful rejection of help in learning something that always stops speculations from being productive, and it has stopped this one cold. At some point you have to acknowledge that you're going to get stuck a lot going down the rabbit hole, and admit it when you're wrong. Thread closed. 2 Link to comment Share on other sites More sharing options...
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